I have already ordered the book, thanks, Peter. It will be interesting to see what additional information I can glean, although... as I pointed out... translating literally without a complete understanding of the idiom of the times, the allegories, the allusions, etc., in relation to the culture can sometimes lead a person to a conclusion that may not be exactly accurate.
In Stevens' work I have also seen no indication that he personally ever trained in the ki and "kei" (essence of what we're calling "kokyu") regimens. So, without implying any personal diminishment of Stevens' abilities, I'm positing (fairly safely, I might add) that Stevens had difficulty with accuracy because he wasn't familiar with the topic.
In Stevens' translation of the essence of Aikido, his one tranlation of the "Eight Powers" is pretty much enough to lay the topic away, even if he translated nothing else. The "Eight Powers" or "Four Poles" are only used in one context, the training of ki and kei (jin)abilities.
The common basal discussion of ki training has to do with combining the ki of heaven with the ki of earth. Even though it is a cosmological concept (the "ki of heaven", the "ki of earth", and Man in the Center or on a bridge between the two), the idea of using the MInd, the Yi, the Will (Ueshiba calls it the "Divine Will" in pretty clear usage, even via translations) in conjunction with the Ki of Heaven, Ki of Earth, etc., again pretty much lays it away. The essence of training yourself to gain ki powers is through subtle exercises of "the ki of heaven" and the "ki of earth" that are related to the mind and fascia-related systems while doing various movements to effect body-wide training of the abilities.
The point I'm getting at is that even without a contextual understanding of what Ueshiba was referring to, the literal or near-literal translations that are available are so solid as to prompt me to bet my house without any reservations whatsoever on the idea that Ueshiba was making pretty standard references to ki-related training.
If nothing else, a translator who knew these topics and how to train them, could not have missed the obvious relationship and, if he thought Ueshiba referred to something else, would have been duty-bound to mention the relationship and give reasons for discounting it.
In addition, if you add the overt ki demonstrations by Ueshiba (which mimic old Chinese demonstrations of qi almost exactly), the basic practices contained within his Misogi rituals (again with direct parallels and definitive Chinese Buddhist heritage to support the idea) the obvious is supported again. If I thought a little bit longer and went more completely through all the other markers, I could probably extend the argument with other examples. However, given the number of similar writings and comments, the "harmony of the universe", etc., I don't think it's all that necessary.
My suggestion is that anyone interested in following the Chinese-related clues which abound in Ueshiba's writings (even the Shinto elements appear to be based on the wuji-taiji cosmology) might consider going beyond debating the exact translations of Ueshiba's writings and go to the Chinese martial sources to see where Ueshiba was drawing his inspiration.